Is it possible to detect a cell phone jammer?

Is there any way to tell if if my cellular signal is being blocked by someone using a personal/handheld jamming device? If so, would it be possible to trace the interference to its source?

I am referring not to the fixed-location types used legitimately by movie theaters and restaurants, but rather the pocket-size ones used by smug, self-important, yet socially crippled cowards who like to assume that everyone else in the world is an obstinate jerk, therefore entitling them to unilaterally control when, where and for how long others converse. This, without even bothering to politely ask the "offenders" to take the call outside.